(1) Field of Invention
The present invention generally relates to methods of maintaining acoustic sensor arrays.
(2) Description of the Prior Art
Diagnosing failures in marine sonar systems is difficult for many reasons. One issue is that these systems operate in a noisy environment where the signal is difficult to separate from other noise. It can be difficult to determine if a sensor is inoperative and causing noise or merely receiving noise. Thus, it is often difficult to know if a sensor is inoperative.
Another issue is created by the complexity of these systems. Some systems feature long lines of fiber optic sensors. These sensors have a plurality of Bragg arrays made into them to reflect light at different frequencies. A plurality of lasers provides light at different frequencies to the sensors. Light reflecting from the sensors is interfered with light provided to a reference loop to give sensor information. This sensor information is converted from optical information to electronic information. The electronic sensor information is often processed in parallel in multiple processing boards. This sensor information can also be provided to a telemetry system to combine multiple streams of information on fewer cables. Many of these components are subject to mechanical deterioration because the system relies on transmission through a fiber optic line deployed from a marine vessel that operates in a harsh environment.
In any case, diagnosing the failing component or components in these types of systems is difficult because failure of one component may appear as failure of multiple components throughout the system.